Background Map (GSHHS Low Res) - Crude Resolution basemap Installed with Opencpn for the initial rough background map. By default, under macOS, it is installed in Contents/SharedSupport/gshhs/ subfolder of the application bundle.

• GSHHG A Global Self-consistent, Hierarchical, High-resolution Geography Database

High resolution background maps can be obtained through the integrated Chart Downloader plugin see GSHHS High Resolution Background Use with Watchdog Landfall alarms and WeatherRouting plugins for land detection.

• Path to this dataset is stored in the BasemapDir configuration key in opencpn.ini.
• As long as it points to Contents/SharedSupport/gshhs/, replacing the content of Contents/SharedSupport/gshhs/ makes OpenCPN use it.
• If BasemapDir points somewhere else, it is not going to be used.
• However if GSHHG data is pointed to a chart folder, the folder is detected and BasemapDir is changed to point to that location.
• Basemap is always displayed, regardless of chart groups.
• Keep your GSHHG dataset up to date using ChartDownloader, please.

The GSHHG High Resolution Background Map is very useful and almost necessary for two plugins that actively use it:

• Watchdog_pi - For Landfall notification
• Weather_routing_pi - For routing optimization with Land Detection.